Static lamination micro mixer

ABSTRACT

Static lamination micro mixer comprising at least one slotted plate having slot openings and an aperture plate having aperture slots arranged above the slotted plate.

The invention relates to a micro-mixer for mixing, dispersing,emulsifying or suspending at least two fluid phases, it being necessaryfor this micro-mixer to have at least one slotted plate having slotopenings and an aperture plate having aperture slots arranged above theformer. The slot openings in the slotted plate(s) and aperture plate(s)are formed as continuous openings. The opening can be shaped as desired;the opening preferably has a simple geometry (for example a hole orrectangular slot).

Static micro-mixers are key elements in micro-reaction technology.Static micro-mixers use the principle of multi-lamination, in order inthis way to achieve rapid mixing of fluid phases by means of diffusion.A geometric configuration of alternately arranged lamellae makes itpossible to ensure good mixing in the microscopic range.Multi-lamination mixers made of structured and periodically stacked thinplates are already extensively described in the literature; examples ofthis will be found in German patents DE 44 16 343, DE 195 40 292 and theGerman patent application DE 199 28 123. In addition, as opposed to themulti-lamination mixers, which comprise structured and periodicallystacked thin plates, the German patent application DE 199 27 554describes a micro-mixer for mixing two or more educts, the micro-mixerhaving mixing cells. Each of these mixing cells has a feed chamber whichis adjoined by at least two groups of channel fingers which engage inthe manner of a comb between the channel fingers in order to form mixingregions. Above the mixing region there are outlet slots, which extend atright angles to the channel fingers and through which the productemerges. As a result of the parallel connection in two spatialdirections, a considerably higher throughput is possible.

The invention specified in Patent claim 1 is based on the problem thatmicro-mixers can clog up with contaminating particles and therefore tendto block; as a result of the inadequate cleaning possibilities, there isa considerable restriction of the possible uses of micro-mixers. In thecase of the micro-mixers constructed from plates, the plates arepreferably permanently connected to one another and, as a result, themicro-structures are no longer freely accessible; cleaning of themicro-mixers described is therefore not possible in a straightforwardmanner. In order to clean a corresponding micro-mixer, the plate stackhas to be dismantled, which generally proves to be very complicated.

These problems are solved by the static lamination micro-mixer describedin Patent claim 1 which, in order to mix at least two fluid phases,contains at least one slotted plate having slot openings and an apertureplate having aperture slots arranged above the former. The slot openingsare generally formed as continuous openings.

The advantages achieved by the invention consist in the fact that thestatic lamination micro-mixer can be produced economically, is easy toclean and the fluids to be mixed are mixed rapidly and effectively withone another. In addition, the pressure loss is so low that it can evenbe used for large throughputs.

Advantageous refinements of the invention are specified in claim 2 andthose following. According to claim 2, the number of aperture slots inthe aperture plate and/or the number of slot openings in the slottedplate can be greater than 1. In the slot openings of the slotted plate,according to claim 3, the fluid flows led out of various regions of thefluid distribution are led in such a way that they enter the slotopening of a slotted or aperture plate located above. According to claim5, the fluid phases come together in the slot openings of the apertureplate. The slot openings in the slotted plate can in this case be offsetparallel to one another and/or arranged in a periodic pattern inrelation to one another. By means of a suitable geometric form andalignment, slot openings according to claim 6 in the slotted plate canpromote the production of secondary effects. These effects can beproduced, for example, by separations of vortices behind the plates orby transverse components from the feed lines. The mixing at themolecular level as a result of diffusion is consequently overlaid bysecondary flows, which lead to a shortening of the diffusion paths andtherefore the mixing times. According to claim 7, the slot openings canbe arranged obliquely in relation to one another. A further refinementpermits the slot openings to be configured in the manner of funnels orlobes. This refinement of the forms can be expedient in order to achievea uniform pressure distribution in the feed channels. This is aprecondition in order to arrive at a uniform mixing quality in theentire component. Furthermore, it is possible for a plurality of slottedplates and/or aperture plates to be arranged offset from one anotherdirectly above one another. Deflection of the flow can be achievedaccording to claim 9 if slotted plates and/or aperture plates locateddirectly above one another or arranged offset from one another are used.The deflection action can be used, according to claim 11, to lead theone or more fluid flows specifically to the metering point of one ormore fluid flows.

The mixing chamber can be fitted above the aperture plate, according toclaim 12. According to claim 13, it is also possible for the apertureslots in the aperture plate to be offset parallel to one another and/orarranged in a periodic pattern in relation to one another. A furtheradvantageous refinement of the invention permits the slot openings inthe slotted plate and the aperture slots in the aperture plate to bearranged rotated at any desired angle, preferably 90°, in relation toone another. According to claim 15, it is additionally possible for theslot openings in the slotted plate and the aperture slots in theaperture plate to have a width of less than 500 μm. In order to improvethe result when mixing liquids, emulsifying or suspending, slot openingswith widths smaller than 100 μm have in particular proven to beworthwhile. The width of the slot openings in the slotted plate is thesame for all fluid phases in the basic type of the mixer. However, ithas been shown that, in the case of combining fluids which differ interms of their viscosity and/or in which the volume flows are in anumerical ratio with one another different from 1:1, it may beadvantageous if the width and/or shape and cross-section of the slotopening in the slotted plate differ for the various fluids. A furtheradvantageous refinement permits the slotted and aperture plates toconsist, partly or completely, of metal, glass, ceramic and plastic orelse of a combination of these materials. According to claim 17, theslotted and aperture plates can be produced by punching, embossing,milling, erosion, etching, plasma etching, laser cutting, laser ablationor by the LIGA technique but preferably by laser cutting or the LIGAtechnique. A further advantageous refinement permits the slotted andaperture plates to comprise a stack of micro-structured thin plates;these thin micro-structured plates can be connected materially to oneanother by means of soldering, welding, diffusion welding or adhesivebonding or with a force fit by means of screwing, pressing (for examplein a housing) or riveting. An advantageous refinement according to claim20 permits the aperture slots in the aperture plate and the slotopenings in the slotted plate to be of branched configuration. Thestatic micro-mixer obtained in this way can, according to claim 21, beaccommodated in a housing provided for the purpose. According to claim22, the housing can contain channels and in this way permits spatialdistribution of the fluids. According to claim 23, these channels can bearranged parallel to one another, radially, concentrically or behind oneanother. In order to achieve a suitable distribution of the speeds alongthe channels, it may be advantageous to maintain or to vary the crosssections over their length, according to claim 24.

According to claim 25, the micro-mixer can be used individually or as aconstituent part of a modularly constructed arrangement for carrying outphysical or chemical conversions or, according to claim 26, togetherwith other functional modules, integrated into one component.

Exemplary embodiments of the inventions are illustrated in the drawingsand will be described in more detail below.

In the drawings:

FIG. 1 shows a schematic illustration of the static micro-mixercomprising a slotted plate and an aperture plate;

FIG. 2 a shows an exploded illustration of a static laminationmicro-mixer comprising lower housing part (10), feed channels (11),slotted plate (20) and aperture plate (30);

FIG. 2 b shows an illustration of a static lamination micro-mixercomprising lower housing part (10), feed channels (11), slotted plate(20) and aperture plate (30);

FIG. 3 a shows a plan view of the feed channels (11), slot openings (22a, 22 b) and aperture slots (31) of a static lamination micro-mixer;

FIG. 3 b shows a plan view of the slot openings of different geometryand orientation (22) in a slotted plate (20) of a static laminationmicro-mixer;

FIG. 3 c shows a plan view of the slot openings of different geometryand orientation (22) in a slotted plate (20) of a static laminationmicro-mixer;

FIG. 3 d shows a plan view of the slot openings of different geometryand orientation (22) in a slotted plate (20), the slot openings for bothfluids overlapping in the plane of the slotted plate;

FIG. 3 e shows a plan view of the slot openings of different geometryand orientation (22) in a slotted plate (20), the slot openings havingdifferent widths and forms;

FIG. 3 f shows a plan view of the slot openings of different geometryand orientation (22) in a slotted plate (20), the slot openings, theaperture slots (31) and/or the feed channels (11) having different andvariable widths and forms;

FIG. 4 a shows a plan view of a static lamination micro-mixer comprisinglower housing part (10), slotted plate (20) and aperture plate (30);

FIG. 4 b shows a plan view of a static lamination micro-mixer;

FIG. 5 shows an exploded illustration of a static micro-mixer;

FIG. 6 shows an exploded illustration of a static micro-mixer with theviewing angle from below;

FIG. 7 a shows a schematic illustration of the lower housing part (10);

FIG. 7 b shows a cross section through lower housing part (10) along theplane B-B;

FIG. 7 c shows a cross section through lower housing part (10) along theplane C-C;

FIG. 8 a shows a schematic illustration of a static micro-mixer havingtwo different slotted plates and slot openings (22, 23) arranged offsetin relation to one another;

FIG. 8 b shows a schematic illustration of an assembled staticlamination micro-mixer having two different slotted plates;

FIG. 9 a shows exploded illustrations of lamination micro-mixers with aparallel offset arrangement of the channels in order to divide thefluids in the housing;

FIG. 9 b shows exploded illustrations of lamination micro-mixers havinga radially concentric arrangement of the channels in order to divide thefluids in the housing;

FIG. 10 shows a lamination micro-mixer (60) (cf. FIG. 9 a) as aconstituent part of an integrated process arrangement together with aheat exchange unit (70).

FIG. 1 shows a schematic illustration of a static lamination micro-mixercomprising lower part 10, a slotted plate 20 and an aperture plate 30.The lower part 10 contains the feed channel 11 a for the fluid A and thefeed channel 11 b for the fluid B. The slotted plate 20 has slotopenings 22 a and 22 b for the fluids A and B, which are fed from thefeed channel 11 a and 11 b. Above the slotted plate 30 there is theaperture plate 30 having an aperture slot 31. In this case, the apertureplate 30 covers the outer region of the slot openings 22 a and 22 b, thecentral region of the slot openings 22 a and 22 b overlapping theaperture slot 31 and remaining free as a result.

FIG. 2 a shows the exploded illustration of a static micro-mixercomprising lower part 10, feed channels 11 a and 11 b, slotted plate 20and aperture plate 30. The feed channels 11 a and 11 b in each casecontain the fluids A and B; above these feed channels there is theslotted plate 20 having the slot openings 22 a and 22 b. Located abovethe latter is the aperture plate 30, whose aperture slots are arrangedat an angle of 90° in relation to the slot openings 22 a and 22 b.

FIG. 2 b shows a schematic illustration of a static micro-mixer, asillustrated in FIG. 2 a, comprising lower part 10, slotted plate 20 andaperture plate 30.

FIG. 3 a shows slot openings 22 a and 22 b arranged as double rows inthe form of slotted regions 21. These slotted regions 21 are fed withfluids through the feed channels 11 a and 11 b. One half of the slotopenings 22 a overlaps the feed channels 11 a, the other overlaps thefeed channels 11 b. In the central region of the double rows, the slotopenings 22 overlap the aperture slot 31 fitted above. The slot openings22 can also be arranged obliquely, as illustrated here.

FIG. 3 b, FIG. 3 c, FIG. 3 d, FIG. 3 e and FIG. 3 f show slot openings22 with different geometric configuration and orientation. Underneaththe slot openings there are the feed channels 11. Above the slotopenings there are the aperture slots 31. The cross sections of the feedchannels 11 and of the aperture slots 31 can vary along the course (FIG.3 f). The slot openings 22 can be widened in the shape of a funnel. Thewidth and form of the slot openings 22 can vary between the fluids (FIG.3 e) and within the fluids (FIG. 3 f).

FIG. 4 a shows the plan view of a lower housing part 10. The lowerhousing part 10 is provided with numerous slot-like feed channels 11 aand 11 b, which are illustrated as displaced alternately to the right orleft. In the slotted plate 20 arranged above it there is the slottedregion 21 illustrated as black bars; here, the slotted region 21 is ineach case positioned between two feed channels 11 a and 11 b, so that itis overlapped by two feed channels. The aperture slots 31 of theaperture plate 30 located above are found centrally above the slottedregions 21 of the slotted plate 20.

FIG. 4 b shows a schematic arrangement of feed channels 11 a and 11 b,slotted regions 21 and aperture slots 31.

FIG. 5 shows the exploded view of a static lamination micro-mixer; themicro-mixer comprises lower housing part 10 and upper housing part 40.Located between the lower housing part 10 and upper housing part 40 arethe slotted plate 20 and the aperture plate 30. In the lower housingpart 10 there is a groove 13, into which a sealing ring 50 can beinserted in order in this way to seal off the micro-mixer with respectto the surroundings. The lower housing part 10 and the upper housingpart 40 are each provided with openings for fixing elements 44, by meansof which the two can be fixed to each other. The lower housing part 10contains on the outer surface two fluid inlet channels 12 a and 12 b forthe fluids A and B to be mixed. Machined on the upper side of the lowerhousing part 10 are numerous slot-like feed channels 11 a and 11 b,which are configured to be lengthened alternately to one or the otherside and can thus be fed with fluid A or fluid B. The slotted plate 20contains numerous slotted regions 21; above the slotted plate 20 thereis fitted the aperture plate 30, which has a large number of apertureslots 31. The upper housing part 40 contains a fluid outlet 42 for thedischarge of the mixture obtained.

FIG. 6 shows, in analogy with FIG. 5, an exploded illustration of astatic lamination micro-mixer with a viewing angle from the underside.The upper housing part 40 contains a large mixing chamber 45, into whichall the aperture slots 31 of the aperture plate 30 open. In order tosupport the aperture plate 30, a plurality of supporting structures 41are fitted in the upper housing part 40.

FIG. 7 a shows the schematic illustration of the lower housing part 10.The lower housing part 10 is provided with feed channels 11 a and 11 bfor the fluids A and B to be mixed. There are fluid inlets 12 a and 12 bon the outer sides of the lower housing part. The cutouts 44 in the fourcorners of the lower housing part 10 permit it to be fixed.

FIG. 7 b shows the cross section through the lower housing part 10 alongthe line B-B in FIG. 7 a. The fluid inlet 12 a continues into the fluidinlet channel 14 for the fluid A. On the upper side of the fluid inletchannel 14 there are the feed channels 11 a for the fluid. On the upperside of the lower housing part 10 there is a groove 13 for the insertionof a sealing ring.

FIG. 7 c shows the cross section through the lower housing part 10 alongthe line C-C in FIG. 7 a. The feed channels 11 a for the fluid A and 11b for the fluid B run alternately parallel without there being any crossconnection between these two feed channels. On the upper side of thelower housing part 10 there is again a groove 13 for the insertion of asealing ring.

FIG. 8 a shows the schematic illustration of a static laminationmicro-mixer having the two different slot openings 22 a/22 b and 23 a/23b. The slot openings 22 a and 22 b of the first slotted plate form thefeed channels for the second slotted plate having small slot openings 23a and 23 b. The slot openings 22 a/22 b and 23 a/23 b are in each caserotated through 90° in relation to one another.

FIG. 8 b shows the plan view of such a static micro-mixer according toFIG. 8 a comprising two different slotted plates, whose slot openingsare rotated through 90° in relation to one another.

FIG. 9 a and FIG. 9 b show two exemplary embodiments of laminationmicro-mixers in an exploded illustration. According to these, the slotopenings in the slotted plate, the slot openings in the aperture plateand also the channels for distributing the fluids can be arranged to beoffset circularly or in parallel.

FIG. 10 shows an exemplary embodiment relating to the use of alamination micro-mixer as a constituent part of an integratedarrangement for carrying out physical-chemical conversions. In the casepresented, lamination micro-mixer (60) and bundled-tube heat exchanger(17) are integrated into one component.

List of Reference Symbols

-   -   10, 10 a Lower housing part    -   11 a Feed channel for fluid A    -   11 b Feed channel for fluid B    -   12 a Fluid inlet for fluid A    -   12 b Fluid inlet for fluid B    -   13 Groove for sealing ring    -   14 Fluid inlet channel    -   20 Slotted plate    -   21 Slotted region    -   22 a Slot opening for fluid A    -   22 b Slot opening for fluid B    -   23 a Slot opening for fluid A    -   23 b Slot opening for Fluid B    -   30 Aperture plate    -   31 Aperture slot    -   40, 40 a, Upper housing part    -   41 Supporting structure    -   42 Fluid outlet    -   44 Opening for fixing element    -   45 Mixing chamber    -   50 Sealing ring    -   60 Micro-mixer    -   70 Bundled-tube heat exchanger

1. A static lamination micro-mixer for mixing, dispersing, emulsifyingor suspending at least two fluid phases, comprising at least one slottedplate having slot openings and an aperture plate having aperture slotsarranged above the former, whose slots are produced as continuousopenings.
 2. Micro-mixer according to claim 1, wherein the number ofslot openings in the slotted plate and/or the number of aperture slotsin the aperture plate is greater than one.
 3. Micro-mixer according toclaim 1, wherein fluid phases supplied to the micro mixer are, afterentering the slotted plate, initially fed to one another in the slotopenings before entering the opening of a plate located above. 4.Micro-mixer according to claim 1, wherein the slot openings in theslotted plate are arranged in relation to one another in such a way thatthe fluid phases enter the slot opening of an aperture or slotted platelocated above.
 5. Micro-mixer according to claim 1, wherein the fluidphases come into contact with one another in the slot openings of theaperture plate.
 6. Micro-mixer according to claim 1, wherein thegeometric form and alignment of the slot openings in the slotted platepromote the production of secondary effects.
 7. Micro-mixer according toclaim 1, wherein the slot openings are arranged obliquely in relation toone another.
 8. Micro-mixer according to claim 1, wherein the crosssection of the slot openings in the plate is configured in the shape ofa funnel or lobe.
 9. Micro-mixer according to claim 1, wherein aplurality of slotted plates and/or aperture plates are arranged directlyabove one another or offset in relation to one another.
 10. Micro-mixeraccording to claim 1, wherein structures are applied to the slottedplates or are machined out of the plates.
 11. Micro-mixer according toclaim 1, wherein, by means of suitable arrangement of one or moreslotted plates and/or aperture plates, a fluid is led to an outletopening of another fluid.
 12. Micro-mixer according to claim 1, whereina mixing chamber is fitted above the aperture plate.
 13. Micro-mixeraccording to claim 1, wherein the aperture slots in the aperture plateare offset parallel to one another and/or are arranged in a periodicpattern in relation to one another.
 14. Micro-mixer according to claim1, wherein the slot openings in the slotted plate and the aperture slotsin the aperture plate are arranged at any desired angle to one another,optionally rotated through 90°.
 15. Micro-mixer according to claim 1,wherein the slot openings in the slotted plate and the aperture slots inthe aperture plate have a width of less than 500 μm.
 16. Micro-mixeraccording to claim 1, wherein the slotted and aperture plates areformed, partly or completely, of metal, glass, ceramic or plastic or ofa combination of these materials.
 17. Micro-mixer according to claim 1,wherein the slotted and aperture plates have been produced by punching,embossing, milling, erosion, etching, plasma etching, laser cutting,laser ablation or by the LIGA technique.
 18. Micro-mixer according toclaim 1, wherein the slotted and aperture plates comprise a stack ofmicro-structured thin plates.
 19. Micro-mixer according to claim 18,wherein the thin micro-structured plates are connected materially bymeans of soldering, welding, diffusion welding or adhesive bonding orwith a force fit by means of screwing, pressing or riveting. 20.Micro-mixer according to claim 1, wherein the aperture slots in theaperture plates and the slot openings in the slotting plates are ofbranched configuration.
 21. Micro-mixer according to claim 1, whereinthe micro-mixer is accommodated in a housing.
 22. Micro-mixer accordingto claim 21, wherein the housing contains channels which promote spatialdistribution of the fluid phases.
 23. Micro-mixer according to claim 22,wherein the channels are arranged offset parallel from one another,radially, concentrically or behind one another in order to distributethe fluids in the housing.
 24. Micro-mixer according to claim 22,wherein the channels are designed with constant or variable crosssections in order to distribute the fluids in the housing.
 25. Methodfor mixing, dispersing, emulsifying or suspending at least two fluidphases, which comprises leading said fluid phases through at least oneslotted plate having slot openings, the slots of which are in the formof continuous openings, and an aperture plate having aperture slotsarranged above the former.
 26. The Micro-mixer of claim 15, wherein saidwidth is less than 10 μm.
 27. The Micro-mixer of claim 17, wherein saidslotted and aperture plates are produced by laser cutting or the LIGAtechnique.